1 /*
2 * Copyright (c) 2011 The WebRTC project authors. All Rights Reserved.
3 *
4 * Use of this source code is governed by a BSD-style license
5 * that can be found in the LICENSE file in the root of the source
6 * tree. An additional intellectual property rights grant can be found
7 * in the file PATENTS. All contributing project authors may
8 * be found in the AUTHORS file in the root of the source tree.
9 */
10
11 /*
12 * decode.c
13 *
14 * This C file contains the internal decoding function.
15 *
16 */
17
18 #include <string.h>
19
20 #include "bandwidth_estimator.h"
21 #include "codec.h"
22 #include "entropy_coding.h"
23 #include "pitch_estimator.h"
24 #include "settings.h"
25 #include "structs.h"
26
27
28
29
WebRtcIsacfix_DecodeImpl(WebRtc_Word16 * signal_out16,ISACFIX_DecInst_t * ISACdec_obj,WebRtc_Word16 * current_framesamples)30 WebRtc_Word16 WebRtcIsacfix_DecodeImpl(WebRtc_Word16 *signal_out16,
31 ISACFIX_DecInst_t *ISACdec_obj,
32 WebRtc_Word16 *current_framesamples)
33 {
34 int k;
35 int err;
36 WebRtc_Word16 BWno;
37 WebRtc_Word16 len = 0;
38
39 WebRtc_Word16 model;
40
41
42 WebRtc_Word16 Vector_Word16_1[FRAMESAMPLES/2];
43 WebRtc_Word16 Vector_Word16_2[FRAMESAMPLES/2];
44
45 WebRtc_Word32 Vector_Word32_1[FRAMESAMPLES/2];
46 WebRtc_Word32 Vector_Word32_2[FRAMESAMPLES/2];
47
48 WebRtc_Word16 lofilt_coefQ15[ORDERLO*SUBFRAMES]; //refl. coeffs
49 WebRtc_Word16 hifilt_coefQ15[ORDERHI*SUBFRAMES]; //refl. coeffs
50 WebRtc_Word32 gain_lo_hiQ17[2*SUBFRAMES];
51
52 WebRtc_Word16 PitchLags_Q7[PITCH_SUBFRAMES];
53 WebRtc_Word16 PitchGains_Q12[PITCH_SUBFRAMES];
54 WebRtc_Word16 AvgPitchGain_Q12;
55
56 WebRtc_Word16 tmp_1, tmp_2;
57 WebRtc_Word32 tmp32a, tmp32b;
58 WebRtc_Word16 gainQ13;
59
60
61 WebRtc_Word16 frame_nb; /* counter */
62 WebRtc_Word16 frame_mode; /* 0 for 20ms and 30ms, 1 for 60ms */
63 WebRtc_Word16 processed_samples;
64
65 /* PLC */
66 WebRtc_Word16 overlapWin[ 240 ];
67
68 (ISACdec_obj->bitstr_obj).W_upper = 0xFFFFFFFF;
69 (ISACdec_obj->bitstr_obj).streamval = 0;
70 (ISACdec_obj->bitstr_obj).stream_index = 0;
71 (ISACdec_obj->bitstr_obj).full = 1;
72
73
74 /* decode framelength and BW estimation - not used, only for stream pointer*/
75 err = WebRtcIsacfix_DecodeFrameLen(&ISACdec_obj->bitstr_obj, current_framesamples);
76 if (err<0) // error check
77 return err;
78
79 frame_mode = (WebRtc_Word16)WEBRTC_SPL_DIV(*current_framesamples, MAX_FRAMESAMPLES); /* 0, or 1 */
80 processed_samples = (WebRtc_Word16)WEBRTC_SPL_DIV(*current_framesamples, frame_mode+1); /* either 320 (20ms) or 480 (30, 60 ms) */
81
82 err = WebRtcIsacfix_DecodeSendBandwidth(&ISACdec_obj->bitstr_obj, &BWno);
83 if (err<0) // error check
84 return err;
85
86 /* one loop if it's one frame (20 or 30ms), 2 loops if 2 frames bundled together (60ms) */
87 for (frame_nb = 0; frame_nb <= frame_mode; frame_nb++) {
88
89 /* decode & dequantize pitch parameters */
90 err = WebRtcIsacfix_DecodePitchGain(&(ISACdec_obj->bitstr_obj), PitchGains_Q12);
91 if (err<0) // error check
92 return err;
93
94 err = WebRtcIsacfix_DecodePitchLag(&ISACdec_obj->bitstr_obj, PitchGains_Q12, PitchLags_Q7);
95 if (err<0) // error check
96 return err;
97
98 AvgPitchGain_Q12 = (WebRtc_Word16)(((WebRtc_Word32)PitchGains_Q12[0] + PitchGains_Q12[1] + PitchGains_Q12[2] + PitchGains_Q12[3])>>2);
99
100 /* decode & dequantize FiltCoef */
101 err = WebRtcIsacfix_DecodeLpc(gain_lo_hiQ17, lofilt_coefQ15, hifilt_coefQ15,
102 &ISACdec_obj->bitstr_obj, &model);
103
104 if (err<0) // error check
105 return err;
106
107 /* decode & dequantize spectrum */
108 len = WebRtcIsacfix_DecodeSpec(&ISACdec_obj->bitstr_obj, Vector_Word16_1, Vector_Word16_2, AvgPitchGain_Q12);
109 if (len < 0) // error check
110 return len;
111
112 // Why does this need Q16 in and out? /JS
113 WebRtcIsacfix_Spec2Time(Vector_Word16_1, Vector_Word16_2, Vector_Word32_1, Vector_Word32_2);
114
115 for (k=0; k<FRAMESAMPLES/2; k++) {
116 Vector_Word16_1[k] = (WebRtc_Word16)WEBRTC_SPL_RSHIFT_W32(Vector_Word32_1[k]+64, 7); //Q16 -> Q9
117 }
118
119 /* ---- If this is recovery frame ---- */
120 if( (ISACdec_obj->plcstr_obj).used == PLC_WAS_USED )
121 {
122 (ISACdec_obj->plcstr_obj).used = PLC_NOT_USED;
123 if( (ISACdec_obj->plcstr_obj).B < 1000 )
124 {
125 (ISACdec_obj->plcstr_obj).decayCoeffPriodic = 4000;
126 }
127
128 ISACdec_obj->plcstr_obj.decayCoeffPriodic = WEBRTC_SPL_WORD16_MAX; /* DECAY_RATE is in Q15 */
129 ISACdec_obj->plcstr_obj.decayCoeffNoise = WEBRTC_SPL_WORD16_MAX; /* DECAY_RATE is in Q15 */
130 ISACdec_obj->plcstr_obj.pitchCycles = 0;
131
132 PitchGains_Q12[0] = (WebRtc_Word16)WEBRTC_SPL_MUL_16_16_RSFT(PitchGains_Q12[0], 700, 10 );
133
134 /* ---- Add-overlap ---- */
135 WebRtcSpl_GetHanningWindow( overlapWin, RECOVERY_OVERLAP );
136 for( k = 0; k < RECOVERY_OVERLAP; k++ )
137 Vector_Word16_1[k] = WEBRTC_SPL_ADD_SAT_W16(
138 (WebRtc_Word16)WEBRTC_SPL_MUL_16_16_RSFT( (ISACdec_obj->plcstr_obj).overlapLP[k], overlapWin[RECOVERY_OVERLAP - k - 1], 14),
139 (WebRtc_Word16)WEBRTC_SPL_MUL_16_16_RSFT( Vector_Word16_1[k], overlapWin[k], 14) );
140
141
142
143 }
144
145 /* --- Store side info --- */
146 if( frame_nb == frame_mode )
147 {
148 /* --- LPC info */
149 WEBRTC_SPL_MEMCPY_W16( (ISACdec_obj->plcstr_obj).lofilt_coefQ15, &lofilt_coefQ15[(SUBFRAMES-1)*ORDERLO], ORDERLO );
150 WEBRTC_SPL_MEMCPY_W16( (ISACdec_obj->plcstr_obj).hifilt_coefQ15, &hifilt_coefQ15[(SUBFRAMES-1)*ORDERHI], ORDERHI );
151 (ISACdec_obj->plcstr_obj).gain_lo_hiQ17[0] = gain_lo_hiQ17[(SUBFRAMES-1) * 2];
152 (ISACdec_obj->plcstr_obj).gain_lo_hiQ17[1] = gain_lo_hiQ17[(SUBFRAMES-1) * 2 + 1];
153
154 /* --- LTP info */
155 (ISACdec_obj->plcstr_obj).AvgPitchGain_Q12 = PitchGains_Q12[3];
156 (ISACdec_obj->plcstr_obj).lastPitchGain_Q12 = PitchGains_Q12[3];
157 (ISACdec_obj->plcstr_obj).lastPitchLag_Q7 = PitchLags_Q7[3];
158
159 if( PitchLags_Q7[3] < 3000 )
160 (ISACdec_obj->plcstr_obj).lastPitchLag_Q7 += PitchLags_Q7[3];
161
162 WEBRTC_SPL_MEMCPY_W16( (ISACdec_obj->plcstr_obj).prevPitchInvIn, Vector_Word16_1, FRAMESAMPLES/2 );
163
164 }
165 /* ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ */
166
167 /* inverse pitch filter */
168 WebRtcIsacfix_PitchFilter(Vector_Word16_1, Vector_Word16_2, &ISACdec_obj->pitchfiltstr_obj, PitchLags_Q7, PitchGains_Q12, 4);
169
170 if( frame_nb == frame_mode )
171 {
172 WEBRTC_SPL_MEMCPY_W16( (ISACdec_obj->plcstr_obj).prevPitchInvOut, &(Vector_Word16_2[FRAMESAMPLES/2 - (PITCH_MAX_LAG + 10)]), PITCH_MAX_LAG );
173 }
174
175
176 /* reduce gain to compensate for pitch enhancer */
177 /* gain = 1.0f - 0.45f * AvgPitchGain; */
178 tmp32a = WEBRTC_SPL_MUL_16_16_RSFT(AvgPitchGain_Q12, 29, 0); // Q18
179 tmp32b = 262144 - tmp32a; // Q18
180 gainQ13 = (WebRtc_Word16) WEBRTC_SPL_RSHIFT_W32(tmp32b, 5); // Q13
181
182 for (k = 0; k < FRAMESAMPLES/2; k++)
183 {
184 Vector_Word32_1[k] = (WebRtc_Word32) WEBRTC_SPL_LSHIFT_W32(WEBRTC_SPL_MUL_16_16(Vector_Word16_2[k], gainQ13), 3); // Q25
185 }
186
187
188 /* perceptual post-filtering (using normalized lattice filter) */
189 WebRtcIsacfix_NormLatticeFilterAr(ORDERLO, (ISACdec_obj->maskfiltstr_obj).PostStateLoGQ0,
190 Vector_Word32_1, lofilt_coefQ15, gain_lo_hiQ17, 0, Vector_Word16_1);
191
192 /* --- Store Highpass Residual --- */
193 for (k = 0; k < FRAMESAMPLES/2; k++)
194 Vector_Word32_1[k] = WEBRTC_SPL_LSHIFT_W32(Vector_Word32_2[k], 9); // Q16 -> Q25
195
196 for( k = 0; k < PITCH_MAX_LAG + 10; k++ )
197 (ISACdec_obj->plcstr_obj).prevHP[k] = Vector_Word32_1[FRAMESAMPLES/2 - (PITCH_MAX_LAG + 10) + k];
198
199
200 WebRtcIsacfix_NormLatticeFilterAr(ORDERHI, (ISACdec_obj->maskfiltstr_obj).PostStateHiGQ0,
201 Vector_Word32_1, hifilt_coefQ15, gain_lo_hiQ17, 1, Vector_Word16_2);
202
203 /* recombine the 2 bands */
204
205 /* Form the polyphase signals, and compensate for DC offset */
206 for (k=0;k<FRAMESAMPLES/2;k++) {
207 tmp_1 = (WebRtc_Word16)WebRtcSpl_SatW32ToW16(((WebRtc_Word32)Vector_Word16_1[k]+Vector_Word16_2[k] + 1)); /* Construct a new upper channel signal*/
208 tmp_2 = (WebRtc_Word16)WebRtcSpl_SatW32ToW16(((WebRtc_Word32)Vector_Word16_1[k]-Vector_Word16_2[k])); /* Construct a new lower channel signal*/
209 Vector_Word16_1[k] = tmp_1;
210 Vector_Word16_2[k] = tmp_2;
211 }
212
213 WebRtcIsacfix_FilterAndCombine1(Vector_Word16_1, Vector_Word16_2, signal_out16 + frame_nb * processed_samples, &ISACdec_obj->postfiltbankstr_obj);
214
215 }
216 return len;
217 }
218